1. Field
Aspects of the invention relate to internal combustion engines and in particular to exhaust-gas recirculation (EGR) valves for internal combustion engines.
2. Discussion of Related Art
It is well known in the field of automotive engineering and, in particular, in connection with emissions and fuel efficiency improvements of internal combustion engines to provide an exhaust-gas recirculation system.
Various types of EGR valve operations are known. For example, to open and close the valve, i.e. to release the valve member from its valve seat and seat the valve on its seat, a translational movement may be employed. In this respect, it is known from EP 0,856,657B1 that a cam is driven in a rotating manner by a drive mechanism and which engages with a translationally movable valve tappet so as to move the valve tappet translationally whenever the cam moves in a rotating manner. In this manner, the valve tappet may be lifted from its valve seat.
Another EGR valve is known from EP 1,245,820A1. In this example, a rotational movement is transferred, as a result of a suitable transmission means, to the valve member. The valve member may be a fold-down valve disk that moves rotationally between an open and a closed position.
DE 2703687A1 relates to a device for controlling an exhaust-gas recirculation system in which a flap that is disposed within the intake manifold and an EGR line protruding into the intake manifold can close in a closed position.
EP1,526,272A1 describes an EGR valve in which the valve member moves in an orbit in such a way that, when the closing movement is nearly complete, the valve member moves toward the valve seat to a certain extent tangentially, i.e. in a generally perpendicular manner relative to the direction of flow through the valve seat.